Snake Game

Warning

This represents a concept that I am actively developing.

A classic Snake game implementation in C with SDL3, featuring both human-playable and AI-controlled modes.

Features

• Person Mode: Play the game yourself using keyboard controls
• Machine Mode: Watch the AI play using a longest-path algorithm
• SDL3-based graphical interface
• Customizable grid size (30x30 by default)
• Circular queue-based snake body management

Project Structure

snake/
├── include/
│   ├── circular_queue.h     # Circular queue header (types and function declarations)
│   ├── circular_queue.c     # Circular queue implementation for snake body
│   └── const.h              # Game constants (grid size, window dimensions, etc.)
├── src/
│   ├── person/
│   │   ├── snake.c          # Console-based game logic (legacy)
│   │   └── snake_ui.c       # SDL3 UI implementation for person mode
│   └── machine/
│       ├── snake.c          # Game logic with AI pathfinding (legacy)
│       └── snake_ui.c       # SDL3 UI implementation for machine mode
├── CMakeLists.txt           # Build configuration
└── algorithm.md             # Documentation of the longest-path algorithm

Requirements

• CMake 3.16 or higher
• SDL3 library
• C11 compiler (GCC, Clang, etc.)
• Math library (libm, typically included with standard C library)

Building

CMake Build (Recommended)

mkdir build
cd build
cmake ..
cmake --build .

The executables will be built in build/bin/:

• snake_person - Human-playable mode
• snake_machine - AI mode

Manual Build (Alternative)

For person mode:

gcc src/person/snake_ui.c include/circular_queue.c -Wall -Wextra -pedantic -lSDL3 -lm -Iinclude -o snake_person

For machine mode:

gcc src/machine/snake_ui.c include/circular_queue.c -Wall -Wextra -pedantic -lSDL3 -lm -Iinclude -o snake_machine

Running

Person Mode

./build/bin/snake_person

Controls:

• Arrow Keys or WASD:
  • ↑ / w - Move up
  • ← / a - Move left
  • ↓ / s - Move down
  • → / d - Move right

Machine Mode

./build/bin/snake_machine

Watch the AI navigate using the longest-path algorithm to maximize survival.

Configuration

Edit include/const.h to customize:

• ROWS and COLUMNS - Grid dimensions (default: 30x30)
• WIDTH and HEIGHT - Window size (default: 1000x1000)
• TIMER - Game speed in milliseconds (default: 75ms)
• PADDING - Visual padding around grid (default: 40px)

After changing constants, rebuild the project:

cmake --build build

Algorithm

The machine mode uses a longest-path algorithm to determine snake movement. The algorithm:

1. Finds paths between consecutive points using DFS/backtracking
2. Iteratively extends path segments to maximize length
3. Avoids creating paths that would trap the snake

See algorithm.md for detailed implementation notes.

Implementation Details

• Circular Queue: The snake body is managed using a circular queue data structure for efficient head/tail operations
• Collision Detection: Checks for wall collisions and self-collisions each frame
• Smooth Rendering: Uses SDL3 textures and incremental updates for optimized rendering
• Input Handling: Prevents opposite direction changes and implements turn buffering

Troubleshooting

If you encounter build errors:

1. Ensure SDL3 is properly installed and findable by CMake
2. Verify you have a C11-compatible compiler
3. Clean the build directory: rm -rf build && mkdir build

If the game doesn't launch:

1. Check SDL3 runtime libraries are in your library path
2. Verify the executable has proper permissions: chmod +x build/bin/snake_person

License

This project is provided as-is for educational purposes.